MoSi_(2)涂层高温富氧火焰冲刷失效机理研究  

Study on Failure Mechanism of MoSi_(2) Coating UnderHigh-Temperature Oxygen-Enriched Flame Erosion

作　　者：罗靖川 朱昌发 刘坤 王钺淞 徐向毅 杨冠军[1] 陈林[1] LUO Jingchuan;ZHU Changfa;LIU Kun;WANG Yuesong;XU Xiangyi;YANG Guanjun;CHEN Lin(State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China;Xi'an Aero Engine Corporation in CASC,Xi'an 710065,China;The Second Military Representative of Equipment Department of the PLA Rocket Force Office in Xi'an,Xi'an 710065,China;The 8th Military Representative of Equipment Department of the Air Force Office in Xi'an,Xi'an 710065,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049 [2]中国航天西安航天发动机有限公司,陕西西安710065 [3]火箭军装备部驻西安地区第二军事代表室,陕西西安710065 [4]空军装备部驻西安地区军事代表局第八军事代表室,陕西西安710065

出　　处：《中国材料进展》2024年第4期355-365,共11页Materials China

基　　金：中国博士后创新人才支持计划项目(BX2021238);国家自然科学基金项目(51671159)。

摘　　要：MoSi_(2)高温氧化时表面可生成保护性SiO_(2),有望用于推力室喷管内表面抗高温氧化涂层材料。然而,在1800℃及以上超高温火焰冲刷考核条件下,MoSi_(2)涂层发生快速损伤失效。为揭示MoSi_(2)涂层超高温冲刷失效机理,系统研究了推力室喷管不同位置涂层的氧化行为和损伤规律。结果表明:涂层损伤分为5个特征区域,分别为前缘、喉部、过渡段、中部和尾部,其中喉部发生整个涂层剥落,尾部涂层仍保持完整。MoSi_(2)涂层的主要失效形式为:超高温下MoSi_(2)涂层晶界快速氧化和氧化膜快速挥发,产生晶界裂纹,晶界裂纹合并形成网状、贯穿性、大尺度的纵向裂纹,将MoSi_(2)涂层分割成岛状区域。在热冲击载荷作用下,岛状区域MoSi_(2)涂层发生剥落失效。指出了MoSi_(2)涂层超高温冲刷腐蚀机理,为发展推力室喷管用长寿命MoSi_(2)超高温抗氧化涂层提供了理论方向。MoSi_(2) can generate protective SiO_(2) on the surface during high temperature oxidation,which is expected to be used as a high-temperature oxidation-resistant coating on the inner surface of the thrust chamber nozzle.However,the MoSi_(2) coatings failed under the flame erosion at temperatures≥1800 ℃.In order to reveal the failure mechanism of MoSi_(2) coatings,the oxidation behavior of coating at various locations of the thrust chamber nozzle specimen after the flame erosion was clarified.The results show that the coating can be divided into five characteristic regions,namely the leading edge,the throat,the transition section,the middle and the tail.Among them,the entire coating peels off at the throat,and the coating remains intact at the tail.The main failure mode of the MoSi_(2) coatings is:rapid oxidation and corrosion at the grain boundaries(GB) of the MoSi_(2) coatings result in the formation of penetrating GB cracks,the coalescence of penetrating GB cracks causes the connected and large-scale vertical cracks,dividing the coatings into island-shaped regions.Under the action of thermal shock,island-shaped coatings peel off.This research analyzes the erosion behavior of MoSi_(2) coating,and provides the reference for the development of long-life ultra-high temperature anti-oxidation MoSi_(2) coatings for thrust chamber nozzles.

关 键 词：MoSi_(2)涂层 氧化膜 晶界 纵向裂纹 剥落 

分 类 号：TG174.4[金属学及工艺—金属表面处理]